A low rocky island 13 kilometres northwest of Anguilla with 3 smaller cays off the west and north coasts. The cliffs and inland areas of scrub are home to Anguilla's largest seabird colonies. The coastline has low cliffs interspersed with 5 sandy beaches. Weathered limestone rocks reach sea level on parts of the west and northeast coast. Two large ponds lie inside beaches at Spring bay and Stoney bay. The centre of the island is covered in impenetrable, low, thorny scrub and thousands of prickly pear cacti. A small herd of c30 feral goats are a remnant of former more extensive grazing by livestock.
At least 28 species have been recorded including 9 species of breeding seabird:Red-billed Tropicbird, Masked Booby, Brown Booby, Magnificent Frigate Bird, Laughing Gull, Least Tern, Bridle Tern, Sooty Tern and Brown Noddy. The site holds the only Anguillan breeding populations of Magnificent Frigate Bird and Sooty Tern. Surveys in May 2007 documented 113,000 Sooty Terns breeding on Dog Island. Two small ponds and several beaches attract non-breeding and passage wildfowl and shorebirds including White-cheeked pintail, Blue-winged teal, and American Oyster Catcher. Wilsons Plover may breed. Both Osprey and Peregrine Falcons have been recorded outside the breeding season and Caribbean Elaenia, Bananaquits, and Blackfaced Grassquits are the only land birds present. The site has been little visited and requires further study.
Non-bird biodiversity: Dog Island holds populations of several species of reptile: a ground lizard Ameiva plei,a tree lizard Anolis gingivinus, Little Dwarf gecko Sphaerodactylus parvus, Island Dwarf gecko Sphaerodactylus sputator and a slippery back Mabouya sp.
BirdLife International (2020) Important Bird Areas factsheet: Dog Island. Downloaded from http://www.birdlife.org on 25/11/2020.